If $x \otimes y = 3x+y$ and $x \boxdot y = x^{2}-2y^{2}$, find $-5 \otimes (6 \boxdot -4)$.
First, find $6 \boxdot -4$ $ 6 \boxdot -4 = 6^{2}-2(-4)^{2}$ $ \hphantom{6 \boxdot -4} = 4$ Now, find $-5 \otimes 4$ $ -5 \otimes 4 = (3)(-5)+4$ $ \hphantom{-5 \otimes 4} = -11$.